package/ci: GitHub says I can't use git:// anymore.

I kinda get the point, to avoid rogue third parties tainting my
ŕepositories with nasty backdoors, yes, but unless *everything* on the
way to the server including DNS queries is encrypted, then it's still
just a half of the solution and any silly corporate firewall can still
prevent me from cloning stuff from github dot com.

package/ci/appveyor-desktop-gles.bat

@@ -5,7 +5,7 @@ rem OpenAL DLL is renamed & copied to magnum's bin dir automatically by the
 rem buildsystem, no need to do that here anymore
 
 rem Build Corrade
-git clone --depth 1 git://github.com/mosra/corrade.git || exit /b
+git clone --depth 1 https://github.com/mosra/corrade.git || exit /b
 cd corrade || exit /b
 mkdir build && cd build || exit /b
 cmake .. ^

package/ci/appveyor-desktop-mingw.bat

@@ -5,7 +5,7 @@ rem OpenAL DLL is renamed & copied to magnum's bin dir automatically by the
 rem buildsystem, no need to do that here anymore
 
 rem Build Corrade
-git clone --depth 1 git://github.com/mosra/corrade.git || exit /b
+git clone --depth 1 https://github.com/mosra/corrade.git || exit /b
 cd corrade || exit /b
 mkdir build && cd build || exit /b
 cmake .. ^

package/ci/appveyor-desktop.bat

@@ -12,7 +12,7 @@ rem currently disabled -- https://github.com/catchorg/Catch2/issues/1113
 if "%COMPILER%" == "msvc-clang" set COMPILER_EXTRA=-DCMAKE_CXX_COMPILER="C:/Program Files (x86)/Microsoft Visual Studio/2019/Community/VC/Tools/Llvm/bin/clang-cl.exe" -DCMAKE_LINKER="C:/Program Files (x86)/Microsoft Visual Studio/2019/Community/VC/Tools/Llvm/bin/lld-link.exe" -DCMAKE_CXX_FLAGS="-m64 /EHsc"
 
 rem Build Corrade
-git clone --depth 1 git://github.com/mosra/corrade.git || exit /b
+git clone --depth 1 https://github.com/mosra/corrade.git || exit /b
 cd corrade || exit /b
 mkdir build && cd build || exit /b
 cmake .. ^

package/ci/appveyor-rt.bat

@@ -10,7 +10,7 @@ cd SDL/VisualC-WinRT/UWP_VS2015 || exit/b
 msbuild /p:Configuration=Release || exit /b
 cd ..\..\..
 
-git clone --depth 1 git://github.com/mosra/corrade.git || exit /b
+git clone --depth 1 https://github.com/mosra/corrade.git || exit /b
 cd corrade || exit /b
 
 rem Build native corrade-rc

package/ci/emscripten.sh

@@ -4,7 +4,7 @@ set -ev
 git submodule update --init
 
 # Corrade
-git clone --depth 1 git://github.com/mosra/corrade.git
+git clone --depth 1 https://github.com/mosra/corrade.git
 cd corrade
 
 # Build native corrade-rc

package/ci/travis-android-gles.sh

@@ -2,7 +2,7 @@
 set -ev
 
 # Corrade
-git clone --depth 1 git://github.com/mosra/corrade.git
+git clone --depth 1 https://github.com/mosra/corrade.git
 cd corrade
 
 # Build native corrade-rc

package/ci/travis-android-vulkan.sh

@@ -2,7 +2,7 @@
 set -ev
 
 # Corrade
-git clone --depth 1 git://github.com/mosra/corrade.git
+git clone --depth 1 https://github.com/mosra/corrade.git
 cd corrade
 
 # Build native corrade-rc

package/ci/travis-ios-simulator.sh

@@ -4,7 +4,7 @@ set -ev
 git submodule update --init
 
 # Corrade
-git clone --depth 1 git://github.com/mosra/corrade.git
+git clone --depth 1 https://github.com/mosra/corrade.git
 cd corrade
 
 # Build native corrade-rc

package/ci/unix-desktop-gles.sh

@@ -2,7 +2,7 @@
 set -ev
 
 # Corrade
-git clone --depth 1 git://github.com/mosra/corrade.git
+git clone --depth 1 https://github.com/mosra/corrade.git
 cd corrade
 mkdir build && cd build
 cmake .. \

package/ci/unix-desktop-vulkan.sh

@@ -2,7 +2,7 @@
 set -ev
 
 # Corrade
-git clone --depth 1 git://github.com/mosra/corrade.git
+git clone --depth 1 https://github.com/mosra/corrade.git
 cd corrade
 mkdir build && cd build
 cmake .. \

package/ci/unix-desktop.sh

@@ -2,7 +2,7 @@
 set -ev
 
 # Corrade
-git clone --depth 1 git://github.com/mosra/corrade.git
+git clone --depth 1 https://github.com/mosra/corrade.git
 cd corrade
 mkdir build && cd build
 cmake .. \